Emergency services were called to the worksite, on the corner of Watts Street and Whitehorse Road, Box Hill, after the crane's chain snapped about 12:20pm.

One of the trapped men died.

An Ambulance Victoria spokeswoman said another man was being transferred to the Royal Melbourne Hospital in a serious condition, and another person with minor injuries had been taken to Box Hill Hospital.

A fire brigade spokeswoman said its specialist urban search and rescue teams and high angle rescue technicians were on the scene.